The analysis of structural, elastic, and electronic properties of Na3N compound under high hydrostatic pressure with the first principles method

Abstract

In the present study, the structural, electronic, and mechanical properties of the sodium nitride (Na3N) were determined under up to 150 GPa hydrostatic pressure with the generalized gradient approach (GGA) based on the density functional theory (DFT). The Na3N compound was transformed from the hexagonal structure with the space group P6/ mmm to the cubic structure with the space group Fm(3)over barm with gradually increasing pressure. Enthalpy and total energy were calculated to observe the consistency of the study findings with experimental results. The calculations revealed that the phase transition of the Na3N compound was observed at about 9.5 GPa from hexagonal structure to cubic structure. Furthermore, the electronic properties of the Na3N compound were investigated in the P6/mmm and Fm(3)over barm phases. The elastic properties of Na3N were determined, and it was concluded that both phases were mechanically stable. Cauchy pressure, Poisson's ratio, Kleinman parameter, and Pugh's ratio were calculated to better understand the elasticity of the material.